Merck, D1315-1MG, DT Diaphorase (NQO1) human

Application
Human DT diaphorase has been used in a study to assess the development of novel quinone phosphorodiamidate prodrugs. Human DT diaphorase has also been used to investigate its crystal structure for the development of a model for its interaction with the cytotoxic prodrug 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954).
Biochem/physiol Actions
DT-diaphorase, also referred to as NAD(P)H:(quinone-acceptor) oxidoreductase, is involved in the reductive activation process of several cytotoxic antitumor quinones and nitrobenzenes. It catalyzes the two-electron reduction of quinones and quinonoid compounds to hydroquinones, using either NADH or NADPH as the electron donor. The flavoenzyme contains one mole of FAD per mole of enzyme.
NQO1 is a cytosolic homodimeric FAD-dependent enzyme that catalyses the reduction of a broad range of cytotoxic quinones resulting in protection from cellular oxidative stress. Oxidative stress may also enhance NQO1-mediated protection of p53 and p73 against proteasomal degredation. The highly Inducible expression of NQO1 is controlled by the Nrf2-Keap1/ARE pathway and appears to be affected by changes in susceptibility to oxidative stress. During Oxygen/glucose deprivation, NQO1 appears to be involved in AMPK-induced cancer cell death. NQO1 has been observed to be overexpressed in several types of solid tumors, including breast, pancreas, lung and colon cancer.
Shown to activate quinone based anti-tumor agents in vivo. Suitable for conjugation to carrier molecules.
Other Notes
One unit will reduce 1.0 μmole cytochrome C per min/mg in the presence of menadione substrate at 37 °C.